X-Git-Url: https://git.lttng.org/?a=blobdiff_plain;f=src%2Fbin%2Flttng-sessiond%2Fkernel.c;h=ae8349c897ded12d90bfc2d018ba1994e1822f63;hb=8d9ce0bc94bfec4b7bd85f16cd068926e3dc7779;hp=2cad0b2ab44b8bdd8ece486521e62f6654677e4d;hpb=890d8fe47755c3bad936389cf48ffa141cff41c9;p=lttng-tools.git

diff --git a/src/bin/lttng-sessiond/kernel.c b/src/bin/lttng-sessiond/kernel.c
index 2cad0b2ab..ae8349c89 100644
--- a/src/bin/lttng-sessiond/kernel.c
+++ b/src/bin/lttng-sessiond/kernel.c
@@ -16,7 +16,6 @@
  */
 
 #define _LGPL_SOURCE
-#include <errno.h>
 #include <fcntl.h>
 #include <stdlib.h>
 #include <stdio.h>
@@ -49,17 +48,24 @@ int kernel_add_channel_context(struct ltt_kernel_channel *chan,
 	DBG("Adding context to channel %s", chan->channel->name);
 	ret = kernctl_add_context(chan->fd, &ctx->ctx);
 	if (ret < 0) {
-		if (errno != EEXIST) {
-			PERROR("add context ioctl");
-		} else {
+		switch (-ret) {
+		case ENOSYS:
+			/* Exists but not available for this kernel */
+			ret = LTTNG_ERR_KERN_CONTEXT_UNAVAILABLE;
+			goto error;
+		case EEXIST:
 			/* If EEXIST, we just ignore the error */
 			ret = 0;
+			goto end;
+		default:
+			PERROR("add context ioctl");
+			ret = LTTNG_ERR_KERN_CONTEXT_FAIL;
+			goto error;
 		}
-		goto error;
 	}
 
+end:
 	cds_list_add_tail(&ctx->list, &chan->ctx_list);
-
 	return 0;
 
 error:
@@ -196,7 +202,7 @@ int kernel_create_event(struct lttng_event *ev,
 
 	ret = kernctl_create_event(channel->fd, event->event);
 	if (ret < 0) {
-		switch (errno) {
+		switch (-ret) {
 		case EEXIST:
 			break;
 		case ENOSYS:
@@ -208,7 +214,6 @@ int kernel_create_event(struct lttng_event *ev,
 		default:
 			PERROR("create event ioctl");
 		}
-		ret = -errno;
 		goto free_event;
 	}
 
@@ -229,7 +234,7 @@ int kernel_create_event(struct lttng_event *ev,
 
 	ret = kernctl_enable(event->fd);
 	if (ret < 0) {
-		switch (errno) {
+		switch (-ret) {
 		case EEXIST:
 			ret = LTTNG_ERR_KERN_EVENT_EXIST;
 			break;
@@ -276,7 +281,6 @@ int kernel_disable_channel(struct ltt_kernel_channel *chan)
 	ret = kernctl_disable(chan->fd);
 	if (ret < 0) {
 		PERROR("disable chan ioctl");
-		ret = errno;
 		goto error;
 	}
 
@@ -299,7 +303,7 @@ int kernel_enable_channel(struct ltt_kernel_channel *chan)
 	assert(chan);
 
 	ret = kernctl_enable(chan->fd);
-	if (ret < 0 && errno != EEXIST) {
+	if (ret < 0 && ret != -EEXIST) {
 		PERROR("Enable kernel chan");
 		goto error;
 	}
@@ -324,7 +328,7 @@ int kernel_enable_event(struct ltt_kernel_event *event)
 
 	ret = kernctl_enable(event->fd);
 	if (ret < 0) {
-		switch (errno) {
+		switch (-ret) {
 		case EEXIST:
 			ret = LTTNG_ERR_KERN_EVENT_EXIST;
 			break;
@@ -355,7 +359,7 @@ int kernel_disable_event(struct ltt_kernel_event *event)
 
 	ret = kernctl_disable(event->fd);
 	if (ret < 0) {
-		switch (errno) {
+		switch (-ret) {
 		case EEXIST:
 			ret = LTTNG_ERR_KERN_EVENT_EXIST;
 			break;
@@ -386,7 +390,7 @@ int kernel_track_pid(struct ltt_kernel_session *session, int pid)
 	if (!ret) {
 		return LTTNG_OK;
 	}
-	switch (errno) {
+	switch (-ret) {
 	case EINVAL:
 		return LTTNG_ERR_INVALID;
 	case ENOMEM:
@@ -408,7 +412,7 @@ int kernel_untrack_pid(struct ltt_kernel_session *session, int pid)
 	if (!ret) {
 		return LTTNG_OK;
 	}
-	switch (errno) {
+	switch (-ret) {
 	case EINVAL:
 		return LTTNG_ERR_INVALID;
 	case ENOMEM:
@@ -829,7 +833,7 @@ int kernel_validate_version(int tracer_fd)
 
 	ret = kernctl_tracer_version(tracer_fd, &version);
 	if (ret < 0) {
-		ERR("Failed at getting the lttng-modules version");
+		ERR("Failed to retrieve the lttng-modules version");
 		goto error;
 	}
 
@@ -841,11 +845,11 @@ int kernel_validate_version(int tracer_fd)
 	}
 	ret = kernctl_tracer_abi_version(tracer_fd, &abi_version);
 	if (ret < 0) {
-		ERR("Failed at getting lttng-modules ABI version");
+		ERR("Failed to retrieve lttng-modules ABI version");
 		goto error;
 	}
 	if (abi_version.major != LTTNG_MODULES_ABI_MAJOR_VERSION) {
-		ERR("Kernel tracer ABI version (%d.%d) is not compatible with expected ABI major version (%d.*)",
+		ERR("Kernel tracer ABI version (%d.%d) does not match the expected ABI major version (%d.*)",
 			abi_version.major, abi_version.minor,
 			LTTNG_MODULES_ABI_MAJOR_VERSION);
 		goto error;
@@ -859,6 +863,7 @@ error_version:
 	ret = -1;
 
 error:
+	ERR("Kernel tracer version check failed; kernel tracing will not be available");
 	return ret;
 }